With NIH funding we have developed BPG (Brain Powered Games), a CCRT (Computerized Cognitive Rehabilitation Therapy) digital games package for HIV+ school children in the sub-Sahara. As a child plays, BPG will gather game data for neurocognitive assessment. BPG has been pilot-tested in HIV+ children. In Study Aim 1 we will evaluate concurrent and predictive validity. Here we will evaluate whether BPG static (baseline) assessment will correspond well to our gold standard static measures (KABC-II, TOVA, CogState). Compared to these, we hypothesize that dynamic BPG assessments will provide for a more sensitive evaluation of brain/behavior function as affected by more proximal factors of HIV exposure, disease and treatment. We also hypothesize that dynamic assessments will be more sensitive to distal developmental risk factors (e.g., SES, nutrition/growth, maternal caregiving quality). In Study Aim 2 we will compare the validity of BPG static and dynamic assessments. Here we will validate BPG static and dynamic assessments with a gold standard of neuropsychological tests previously used with children 5 -12 years old at our two study sites (Kampala, Uganda and Blantyre, Malawi). Children will be in 3 cohorts: 1) HIV-positive; 2) HIV exposed and uninfected (HEU); 3) HIV unexposed and uninfected (HUU). Cohorts will be well characterized due to participating in our previous NIH-sponsored HIV clinical trials. We hypothesize that BGP-based static and dynamic assessments will be sensitive to cohorts? prior longitudinal trajectories as affected by proximal and distal risk factors that cause developmental delay and cognitive problems, as measured in our previous clinical trial studies with these cohorts. In Study Aim 3 we will test the sensitivity of dynamic assessment to learning loss after training ends. An advantage of dynamic assessment should be its sensitivity to learning loss over time as a measure of strength of positive neuroplasticity in brain/behavior functions. Here we will test sensitivity by evaluating all 3 cohorts with BPG and gold standard tests (KABC-II, TOVA, CogState) 6 months after the children complete their 12 sessions of BPG training. We hypothesize that BPG dynamic assessment of learning loss at 6-month follow- up post-CCRT will be especially sensitive to integrity of brain/behavior function in pediatric HIV. Overall Impact: BPG will be the first CCRT validated for dual cognitive assessment, both static and dynamic. We expect BPG?s dynamic assessment capability will provide fundamental new insights into how HIV disease and treatment affects brain development, enabling sensitive and accessible cognitive measurement tools for clinical trials. BPG can also be an accessible and inexpensive assessment tool in resource-constrained settings to enable community health workers to monitor brain development in children burdened by other diseases and injuries. It can do so as a mobile-based tablet or smart phone device lending itself to easy scalability of language-free cognitive testing, which can be done as part of cognitive rehabilitation intervention.